wolfSSL up to 5.8.x sp_256_get_entry_256_9 information exposure

Summaryinfo

A vulnerability has been found in wolfSSL up to 5.8.x and classified as problematic. The affected element is the function sp_256_get_entry_256_9. Performing a manipulation results in information exposure. This vulnerability was named CVE-2026-3580. The attack needs to be approached locally. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in wolfSSL up to 5.8.x. It has been classified as problematic. This affects the function sp_256_get_entry_256_9. The manipulation with an unknown input leads to a information exposure vulnerability. CWE is classifying the issue as CWE-203. The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not. This is going to have an impact on confidentiality. The summary by CVE is:

In wolfSSL 5.8.4, constant-time masking logic in sp_256_get_entry_256_9 is optimized into conditional branches (bnez) by GCC when targeting RISC-V RV32I with -O3. This transformation breaks the side-channel resistance of ECC scalar multiplication, potentially allowing a local attacker to recover secret keys via timing analysis.

The weakness was presented by Wind Wong. The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-3580 since 03/05/2026. The exploitability is told to be difficult. An attack has to be approached locally. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 303115 (Linux Distros Unpatched Vulnerability : CVE-2026-3580), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.9.0 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (303115) and EUVD (EUVD-2026-13172). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• wolfSSL

Version

• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 5.5
• 5.6
• 5.7
• 5.8

License

• open-source

Website

• Product: https://github.com/wolfSSL/wolfssl/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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